/src/libzip/lib/zip_source_seek.c

Source
/*
  zip_source_seek.c -- seek to offset
  Copyright (C) 2014-2024 Dieter Baron and Thomas Klausner

  This file is part of libzip, a library to manipulate ZIP archives.
  The authors can be contacted at <info@libzip.org>

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:
  1. Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
  2. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in
     the documentation and/or other materials provided with the
     distribution.
  3. The names of the authors may not be used to endorse or promote
     products derived from this software without specific prior
     written permission.

  THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
  IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
  IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/


#include "zipint.h"


ZIP_EXTERN int
zip_source_seek(zip_source_t *src, zip_int64_t offset, int whence) {
    zip_source_args_seek_t args;

    if (src->source_closed) {
        return -1;
    }
    if (!ZIP_SOURCE_IS_OPEN_READING(src) || (whence != SEEK_SET && whence != SEEK_CUR && whence != SEEK_END)) {
        zip_error_set(&src->error, ZIP_ER_INVAL, 0);
        return -1;
    }

    args.offset = offset;
    args.whence = whence;

    if (_zip_source_call(src, &args, sizeof(args), ZIP_SOURCE_SEEK) < 0) {
        return -1;
    }

    src->eof = 0;
    return 0;
}


zip_int64_t
zip_source_seek_compute_offset(zip_uint64_t offset, zip_uint64_t length, void *data, zip_uint64_t data_length, zip_error_t *error) {
    zip_int64_t new_offset;
    zip_source_args_seek_t *args = ZIP_SOURCE_GET_ARGS(zip_source_args_seek_t, data, data_length, error);

    if (args == NULL) {
        return -1;
    }

    switch (args->whence) {
    case SEEK_CUR:
        new_offset = (zip_int64_t)offset + args->offset;
        break;

    case SEEK_END:
        new_offset = (zip_int64_t)length + args->offset;
        break;

    case SEEK_SET:
        new_offset = args->offset;
        break;

    default:
        zip_error_set(error, ZIP_ER_INVAL, 0);
        return -1;
    }

    if (new_offset < 0 || (zip_uint64_t)new_offset > length) {
        zip_error_set(error, ZIP_ER_INVAL, 0);
        return -1;
    }

    return new_offset;
}

Line	Count	Source
1		/*
2		zip_source_seek.c -- seek to offset
3		Copyright (C) 2014-2024 Dieter Baron and Thomas Klausner
4
5		This file is part of libzip, a library to manipulate ZIP archives.
6		The authors can be contacted at <info@libzip.org>
7
8		Redistribution and use in source and binary forms, with or without
9		modification, are permitted provided that the following conditions
10		are met:
11		1. Redistributions of source code must retain the above copyright
12		notice, this list of conditions and the following disclaimer.
13		2. Redistributions in binary form must reproduce the above copyright
14		notice, this list of conditions and the following disclaimer in
15		the documentation and/or other materials provided with the
16		distribution.
17		3. The names of the authors may not be used to endorse or promote
18		products derived from this software without specific prior
19		written permission.
20
21		THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
22		OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23		WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24		ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
25		DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26		DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27		GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28		INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
29		IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
30		OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
31		IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32		*/
33
34
35		#include "zipint.h"
36
37
38		ZIP_EXTERN int
39	132k	zip_source_seek(zip_source_t *src, zip_int64_t offset, int whence) {
40	132k	zip_source_args_seek_t args;
41
42	132k	if (src->source_closed) {
43	0	return -1;
44	0	}
45	132k	if (!ZIP_SOURCE_IS_OPEN_READING(src) \|\| (whence != SEEK_SET && whence != SEEK_CUR && whence != SEEK_END)) {
46	0	zip_error_set(&src->error, ZIP_ER_INVAL, 0);
47	0	return -1;
48	0	}
49
50	132k	args.offset = offset;
51	132k	args.whence = whence;
52
53	132k	if (_zip_source_call(src, &args, sizeof(args), ZIP_SOURCE_SEEK) < 0) {
54	8.94k	return -1;
55	8.94k	}
56
57	123k	src->eof = 0;
58	123k	return 0;
59	132k	}
60
61
62		zip_int64_t
63	132k	zip_source_seek_compute_offset(zip_uint64_t offset, zip_uint64_t length, void data, zip_uint64_t data_length, zip_error_t error) {
64	132k	zip_int64_t new_offset;
65	132k	zip_source_args_seek_t *args = ZIP_SOURCE_GET_ARGS(zip_source_args_seek_t, data, data_length, error);
66
67	132k	if (args == NULL) {
68	0	return -1;
69	0	}
70
71	132k	switch (args->whence) {
72	30.8k	case SEEK_CUR:
73	30.8k	new_offset = (zip_int64_t)offset + args->offset;
74	30.8k	break;
75
76	9.52k	case SEEK_END:
77	9.52k	new_offset = (zip_int64_t)length + args->offset;
78	9.52k	break;
79
80	92.0k	case SEEK_SET:
81	92.0k	new_offset = args->offset;
82	92.0k	break;
83
84	0	default:
85	0	zip_error_set(error, ZIP_ER_INVAL, 0);
86	0	return -1;
87	132k	}
88
89	132k	if (new_offset < 0 \|\| (zip_uint64_t)new_offset > length) {
90	8.94k	zip_error_set(error, ZIP_ER_INVAL, 0);
91	8.94k	return -1;
92	8.94k	}
93
94	123k	return new_offset;
95	132k	}

Coverage Report

Created: 2026-01-10 06:41